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Hatepe Eruption
The Hatepe eruption, named for the Hatepe Plinian pumice tephra layer, sometimes referred to as the Taupō eruption or Horomatangi Reef Unit Y eruption, is dated to 232 CE ± 10 and was Taupō Volcano's most recent major eruption. It is thought to be New Zealand's largest eruption within the last 20,000 years. The eruption ejected some of material, of which just over was ejected in a few minutes. This makes it one of the largest eruptions in the last 5,000 years, comparable to the Minoan eruption in the 2nd millennium BCE, the 946 eruption of Paektu Mountain, the 1257 eruption of Mount Samalas, and the 1815 eruption of Mount Tambora. Stages of the eruption The eruption went through several stages, with six distinct marker horizons identified. Despite the uniform composition of the erupted magma, a wide variety of eruptive styles were displayed, including weak phreatomagmatism, Plinian eruptions, and a huge pyroclastic flow. Rhyolitic lava domes were extruded some ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Taupō
Lake Taupō (also spelled Taupo; mi, Taupō-nui-a-Tia or ) is a large crater lake in New Zealand's North Island, located in the caldera of the Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's northeastern shore. With a surface area of , it is the largest lake by surface area in New Zealand, and the second largest freshwater lake by surface area in geopolitical Oceania after Lake Murray in Papua New Guinea. Motutaiko Island lies in the southeastern area of the lake. Lake Taupō has a perimeter of approximately and a maximum depth of . It is drained by the Waikato River (New Zealand's longest river), and its main tributaries are the Waitahanui River, the Tongariro River, and the Tauranga Taupō River. It is a noted trout fishery with stocks of introduced brown and rainbow trout. The level of the lake is controlled by Mercury Energy, the owner of the eight hydroelectric dams on the Waikato River downstream of Lake Taupō, usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Holocene (journal)
''The Holocene'' is a peer-reviewed scientific journal that covers research in the field of environmental studies, in particular environmental change over the last c. 11,500 years, particularly the interface between the long Quaternary record and the natural and human-induced environmental processes operating at the Earth's surface today. It is published eight times a year by SAGE Publications. The editor-in-chief is John A. Matthews (University of Wales, Swansea). Scope Included within the scope of ''The Holocene'', according to the journal's website, are articles related to: * "Geological, biological and archaeological evidence of recent climate change; * "Interdisciplinary studies of environmental history and prehistory; * "The development of natural and cultural landscapes and ecosystems; and * "The prediction of future changes in the environment from the record of the past." [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1883 Krakatoa Eruption
The 1883 eruption of Krakatoa ( id, Letusan Krakatau 1883) in the Sunda Strait occurred from 20 May until 21 October 1883, peaking in the late morning hours of 27 August when over 70% of the island of Krakatoa and its surrounding archipelago were destroyed as it collapsed into a caldera. The eruption was one of the deadliest and most destructive volcanic events in recorded history. The explosion was heard away in Perth, Western Australia, and Rodrigues near Mauritius, away. The sound wave is recorded to have travelled around the globe seven times. At least 36,417 deaths are attributed to the eruption and the tsunamis it created. Significant additional effects were also felt around the world in the days and weeks after the volcano's eruption. Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek's subsequent investigation into the eruption. Early phase In the years before the 1883 eruption, seismic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsunami Deposit
A tsunami deposit (the term tsunamiite is also sometimes used) is a sedimentary unit deposited as the result of a tsunami. Such deposits may be left onshore during the inundation phase or offshore during the 'backwash' phase. Such deposits are used to identify past tsunami events and thereby better constrain estimates of both earthquake and tsunami hazards. There remain considerable problems, however, in distinguishing between deposits caused by tsunamis and those caused by storms or other sedimentary processes. Tsunamiite The term "tsunamiite" or "tsunamite" was introduced in the 1980s to describe deposits interpreted to have been formed by traction processes associated with tsunamis and is particularly used for marine deposits formed during the "backwash" phase. The term's application has broadened to encompass all tsunami-related deposits, but its use has been challenged. The main criticism of the term is that it describes deposits that have formed by many different processes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Māori People
The Māori (, ) are the indigenous Polynesian people of mainland New Zealand (). Māori originated with settlers from East Polynesia, who arrived in New Zealand in several waves of canoe voyages between roughly 1320 and 1350. Over several centuries in isolation, these settlers developed their own distinctive culture, whose language, mythology, crafts, and performing arts evolved independently from those of other eastern Polynesian cultures. Some early Māori moved to the Chatham Islands, where their descendants became New Zealand's other indigenous Polynesian ethnic group, the Moriori. Initial contact between Māori and Europeans, starting in the 18th century, ranged from beneficial trade to lethal violence; Māori actively adopted many technologies from the newcomers. With the signing of the Treaty of Waitangi in 1840, the two cultures coexisted for a generation. Rising tensions over disputed land sales led to conflict in the 1860s, and massive land confiscations, to which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrounding atmosphere. New Zealand geologist Patrick Marshall (1869-1950) coined the term ''ignimbrite'' from the Latin ''igni-'' [fire] and ''imbri-'' [rain]. Ignimbrites are made of a very poorly sorted mixture of volcanic ash (or tuff when Lithification, lithified) and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of glass shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified (solidified) rock called lapilli-tuff. Near the volcanic source, ignimbrites often contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown, or black depending on their composition and d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Tongariro
Mount Tongariro (; ) is a compound volcano in the Taupō Volcanic Zone of the North Island of New Zealand. It is located to the southwest of Lake Taupō, and is the northernmost of the three active volcanoes that dominate the landscape of the central North Island. Geology Mount Tongariro is part of the Tongariro volcanic centre, which consists of four massifs made of andesite: Tongariro, Kakaramea-Tihia Massif, Pihanga, and Ruapehu at the southern end of the North Island Volcanic Plateau. The andesitic eruptions formed Tongariro, a steep stratovolcano, reaching a height of . Tongariro is composed of layers of both lava and tephra and the eruptions that built the current stratovolcano commenced about 275,000 years ago. Tongariro consists of at least 12 cones. Ngāuruhoe, while often regarded as a separate mountain, is geologically a cone of Tongariro. It is also the most active vent, having erupted more than 70 times since 1839, the last episode in 1973 to 1975. Activity h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaimanawa Ranges
The Kaimanawa Range of mountains (often known as the ''Kaimanawas'') is located in the central North Island of New Zealand. They extend for 50 kilometres in a northeast/southwest direction through largely uninhabited country to the south of Lake Taupō, east of the "Desert Road". Their slopes form part of the North Island Volcanic Plateau. The New Zealand Ministry for Culture and Heritage gives a translation of "breath for food" for ''Kaimanawa''. The lands around the mountains are scrubby. To the west, where the Rangipo Desert is located, the soils are poor quality. To the east, the soils are more fertile, but the land is very rough. A feral horse, the Kaimanawa horse. roams free on the ranges. Unlike the majority of mountain ranges in New Zealand, the Kaimanawa Range is divided into private land. Considerable areas of the Rangipo Desert are used by the New Zealand Army for training. Demographics Kaimanawa covers and had an estimated population of as of with a population den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waitahanui
Waitahanui is a village in the Taupō District, Waikato region, New Zealand. The village is on the eastern shore of Lake Taupō, south of the district seat of Taupō . Waitahanui Marae and Pākira meeting house is a meeting place for the Ngāti Tūwharetoa hapū of Ngāti Hinerau and Ngāti Tutemohuta. The Waitahanui Bridge site is also a meeting place for the Ngāti Tūwharetoa hapū. Demographics Statistics New Zealand describes Five Mile Bay-Waitahanui as a rural settlement, which covers . The settlement is part of the larger Waitahanui statistical area. Five Mile Bay-Waitahanui had a population of 555 at the 2018 New Zealand census, an increase of 141 people (34.1%) since the 2013 census, and an increase of 102 people (22.5%) since the 2006 census. There were 177 households, comprising 267 males and 282 females, giving a sex ratio of 0.95 males per female, with 108 people (19.5%) aged under 15 years, 87 (15.7%) aged 15 to 29, 240 (43.2%) aged 30 to 64, and 108 (19.5%) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horomatangi Reef
The Horomatangi Reef or reefs is a feature of Lake Taupō, in the central North Island of New Zealand. The reef is named after Horomātangi (Horo-matangi), the tāniwha or water monster of the lake, who is said to reside in a cave adjacent to the nearby Motutaiko Island to the south. The name Horomatangi Reefs perhaps better reflects its complex inner and outer structure with the shallow reefs separated by very deep areas, so tends to be used in the geological literature, while the term reef tends to be used geographically. Geology The reefs are at a high heat-output geothermal hot spot area within the Taupō Volcano. This is related to rhyolitic lava domes extruded after explosive volcanism including the VEI 7 Hatepe eruption of 232 ± 10 CE that ejected over of material (also known as Horomatangi Reef Unit Y eruption) and its linear line of eruption centres, as well as its own namesake Horomatangi, Unit S VEI 6 eruption of about 1460 BCE. Accordingly th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on Earth are lava dome forming. The geochemistry of lava domes can vary from basalt (e.g. Semeru, 1946) to rhyolite (e.g. Chaiten, 2010) although the majority are of intermediate composition (such as Santiaguito, dacite-andesite, present day) The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite. Existence of lava domes has been suggested for some domed structures on the Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
